This article contains some great information that can increase the field of success for your affiliate promotion.
It is vital that you nor your affiliate partners take advantage of this process. The best you can do with cookie stuffing is annoy your readers. It could even break chains used for tracking affiliates and perhaps give users viruses.
You should look at how your affiliate partnerships to a regular and thorough performance review. Getting rid of poor performing affiliates gives you a chance to make more room for better paying advertisers.